A	Ampere, unit of electrical current, coulomb  per second (C·s−1)
Å	Ångstrom, 10−10 m or 0.l nm
C	Charge, coulomb, ampere· second (A. s)
°K	Degrees of temperature, Kelvin (absolute); °C  for degrees Celsius = 273.15 + °K
dyn	Dyne, force, g·cm·s−2 = 10−5 N (newton)
eq	Equivalent weight = molecular weight/va-  lence. One equivalent carries 9.65 × 104 C  of charge
e	Elementary charge, 1.6021892 × 10−19 C
erg	Energy, dyn·cm = g·cm2·s−2 = 10−7 J
F	Faraday constant, 9.648456 × 104 elementary  charge. eq−1 = 96,484.6 C· mol−1 = NAe
g	Acceleration due to gravity = 980.665 cm·s−2
h	Planck’s constant (energy quantum) =  6.626176 × 10−27 erg·s = 6.626 × 10−34 J·s
η	Viscosity; 1 poise (P) = 1 cm−1· g·s−1 = 0.1  Pascal·second (Pa·s)
I	Current, amperes
J	Joule = Watt·second (W ·s) = ampere·volt·  second (A·V·s) = 107 erg = 107 cm2g·s−2
k	Boltzmann constant, 1.380662 × 10−23 J. °K−1  = R/NA, the gas constant over Avogadro’s  number = 1.37900 × 10−16 cm2·g·s−2·°K−1
1, liter	Liter = 1 dm3 = 1,000 cm3. Also milliliter (ml)  and microliter (μl)
M	Mol/l (molarity)
mol/kg	Mol solute/kg solvent (molality)
N	Newton = 105 dyn = 105 cm·g·s−2
N A	Avogadro’s number, 6.022045 × 1023 mol−1,  the number of molecules contained in 1 mol
ns, nw	Number of moles of solute and water
P	Pressure (= force per unit area), N·m−2 or Pa  (Pascal). (1 Pa ≡ 1 N·m−2 ≡ 10 g·cm−1·s−2  ≡ 10−2 mbar ≡ 0.10197 mmH20 ≡ 7.5 ×  10−3 mmHg ≡ 9.869 × 10−6 atm; or 1 atm =  101325 Pa = 760 Torr; 1 cmH20 (at density  1 g·cm−3) = 98.0665 Pa = 981 g·cm−1·s−2;  1 mmHg = 1.00000014 Torr = 133.322 Pa  = 1,333 g·cm−1 · s−2
ρ	Density, g·cm−3. Water (3.98°C, 1 atm) =  0.999972 g·cm−3. Mercury (0°C, 1 atm) =  13.59508 g·c−3
R	Resistance, electrical (Ω), or electrophysiolog-  ical (Ω/cm2) or vascular (a pressure divided  by a flow)
R	Universal gas constant = 8.31441 J.mol−1  °K−1 = 8.3144 × 107 cm2 ·g·s−2 ·mol−1 °K−1  = 0.082 1· atm· mol−1 °K−1 = 0.0623 mmHg·  mmol−1· °K−1 = 8.31441 × 10−7 erg·mol−1·  °K−1
RT	Energy/mol, gas constant × absolute temper-  ature; e.g., at 37°C or 310.16°K, RT = 19.34  × 106 mmHg· cm3· mol−1
RT/F	24.84 mV at 15°C.26.62 mV at 37°C. Values  of loge,10 RT/F at 15, 20, 25, 30, and 37°C  are 57.2, 58.2, 59.2, 60.2, and 61.3 mV
STP	Standard temperature and pressure (ice point  of water, 0°C = 273.16°K; 760 mmHg = 1  atm = 1.01325 × 106 dyn·cm−2 = 1.013 ×  105 N· m−2)
T	Temperature, absolute, in degrees Kelvin  (°K); 0°C = 273.16 °K
V	Volts; millivolt, mV; microvolt, μV
Ṽ i	Partial molar volume, ml/m01 =  (∂V/∂ni)T,p,njj≠i = change of volume of total  system per mole additional solute i, at T, p,  and constant presence of other components  j, and at the particular concentration ni/V.  (ṼW is the partial molar volume of water;  close to 18 ml/mol for physiological solu-  tions)
Watt	Unit of power, joules per second, J·s−1
Work	Work is energy × time or force × distance ×  time, erg·s or J· s or cm2g·s−1
Ω	Ohm, unit of electrical resistance; V/I